+ use the inferred return type in error reporting when no return type is
declared. This turned up in this particular case where we report an
error between the returned value and the inferred return type.
Closes#42546
Change-Id: I48da24047f2e92ca91a514dfcb43c2ba6f65ee46
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/153610
Reviewed-by: Erik Ernst <eernst@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>